ASTM A542 Low Alloy Steel Flange, Grade A, Class 4

1,We Manufacturing processes are primarily classified into four types: 1:Forging, 2:Casting, 3:Cutting, 4:Rolling. 2,We can manufacture in accordance with these standards. Standards: GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards). Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others. The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500. Flange Classification 1. **According to Chemical Industry Standards:** Flanges are classified as follows: Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)). 2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows: Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation). 3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows: Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange. 4. **According to Connection Method/Type:** Flanges are classified as follows: Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc. 5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges. 6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges. A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts." -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel Flange, Grade A, Class 4 Product Information -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel Flange, Grade A, Class 4 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A542 Low Alloy Steel, Grade A, Class 4 Product Information -:- For detailed product information, please contact sales. -: ### **ASTM A542 Grade A Class 4: Ultra-High Strength Chromium-Molybdenum Steel Plate** #### **1. Overview** ASTM A542 Grade A Class 4 is a **premium ultra-high strength chromium-molybdenum alloy steel plate** that represents the highest performance tier within the ASTM A542 specification. This advanced material is supplied in the **quenched and tempered condition** and is specifically engineered for the most demanding pressure vessel applications where maximum strength retention at elevated temperatures is critical. Class 4 provides exceptional mechanical properties while maintaining sufficient toughness for service in extreme refinery, petrochemical, and power generation environments. #### **2. Chemical Composition** The chemical composition features enhanced control for superior performance: | Element | Composition (%) | |---------|-----------------| | Carbon (C) | 0.15 max | | Manganese (Mn) | 0.30 - 0.60 | | Phosphorus (P) | 0.020 max | | Phosphorus (P) | 0.020 max | | Sulfur (S) | 0.015 max | | Silicon (Si) | 0.15 - 0.40 | | Chromium (Cr) | 1.00 - 1.50 | | Molybdenum (Mo) | 0.45 - 0.60 | | Vanadium (V) | 0.03 max (optional) | **Premium Composition Features:** - **Ultra-Low Carbon (0.15% max)**: Ensures exceptional weldability despite ultra-high strength levels - **Enhanced Chromium-Molybdenum System**: Delivers superior high-temperature strength and microstructural stability - **Ultra-Low Impurity Levels**: Maximum 0.020% P and 0.015% S for premium toughness - **Optional Vanadium Addition**: Provides additional precipitation strengthening for specialized applications #### **3. Physical & Mechanical Properties** **Mechanical Properties (Quenched & Tempered Condition):** | Property | Requirement | |----------|-------------| | **Tensile Strength** | 105 - 125 ksi (725 - 860 MPa) | | **Yield Strength** | 80 ksi min (550 MPa min) | | **Elongation in 2 inches** | 15% min | | **Reduction of Area** | 35% min | | **Charpy V-Notch Impact** | 25 ft-lb min at -50°F (-46°C) | **Elevated Temperature Capabilities:** - **Exceptional Creep Strength**: Outstanding resistance to deformation at temperatures up to 1150°F (620°C) - **Superior Oxidation Resistance**: Enhanced performance in aggressive high-temperature environments - **Excellent Thermal Fatigue Resistance**: Maintains integrity under severe thermal cycling conditions - **Microstructural Stability**: Premium resistance to temper embrittlement and microstructural degradation **Physical Properties (Typical):** - **Density**: 0.283 lb/in³ (7,835 kg/m³) - **Modulus of Elasticity**: 29,000 ksi (200 GPa) at 70°F (21°C) - **Mean Coefficient of Thermal Expansion**: 6.5 × 10⁻⁶/°F (11.7 × 10⁻⁶/°C) from 70-1000°F - **Thermal Conductivity**: 25.5 W/m·K at 212°F (100°C) - **Specific Heat**: 0.11 Btu/lb·°F (460 J/kg·K) at 212°F #### **4. Product Applications** Grade A Class 4 is reserved for the most critical high-temperature, high-pressure applications: **Advanced Petroleum Refining:** - Ultra-high pressure hydrocracking reactors - Severe service hydroprocessing units - Advanced refinery conversion systems - Critical high-pressure high-temperature separators **Power Generation Excellence:** - Advanced ultra-supercritical boiler components - High-pressure turbine casings and components - Critical power plant piping systems - Next-generation energy system pressure boundaries **Chemical Process Leadership:** - Severe service chemical synthesis reactors - High-pressure polymerization vessels - Advanced petrochemical processing equipment - Critical process industry pressure containment #### **5. International Standards & Equivalents** | Region/Country | Standard | Equivalent Grade | Notes | |----------------|----------|------------------|-------| | **International** | **ISO 9328-2** | 13CrMo4-5 | Premium high-strength variant | | **Europe** | **EN 10028-2** | 13CrMo4-5 | Enhanced high-temperature properties | | **Japan** | **JIS G4109** | SCMV 4 | Ultra-high strength specialized grade | | **Germany** | **DIN 17155** | 13CrMo44 | Premium quality designation | **Complete Grade A Performance Spectrum:** | Parameter | Class 1 | Class 2 | Class 3 | Class 4 | |-----------|---------|---------|---------|---------| | **Yield Strength Minimum** | 50 ksi | 60 ksi | 70 ksi | 80 ksi | | **Tensile Strength Range** | 75-95 ksi | 85-105 ksi | 95-115 ksi | 105-125 ksi | | **Impact Energy** | 40 ft-lb | 35 ft-lb | 30 ft-lb | 25 ft-lb | #### **6. Fabrication & Quality Excellence** **Advanced Welding Technology:** - **Critical pre-heat control**: 425-525°F (218-274°C) minimum - **Precision interpass management**: 475-575°F (246-302°C) maximum - **Optimized PWHT**: 1200-1300°F (649-704°C) with strict control - **Premium welding consumables**: Specially formulated for ultra-high strength applications - **Advanced procedure qualification**: Essential for all fabrication activities **State-of-the-Art Heat Treatment:** - **Precision austenitizing**: 1650-1700°F (899-927°C) with advanced control systems - **Advanced quenching technology**: Optimized cooling rate management - **Multiple-stage tempering**: 1250-1400°F (677-760°C) for property optimization - **Real-time process monitoring**: Comprehensive digital verification and documentation **Uncompromising Quality Assurance:** - **Advanced ultrasonic examination**: Phased array or TOFD methods per ASTM A578 Level III - **Comprehensive mechanical testing**: Including advanced fracture mechanics characterization - **Metallurgical verification**: Sophisticated microstructural and inclusion analysis - **Complete digital traceability**: Blockchain-enabled documentation systems --- **Breakthrough Technical Advantages:** - **Ultimate strength capability** within chromium-molybdenum steel family - **Exceptional high-temperature performance** in severe service conditions - **Superior resistance to environmental degradation** - **Premium quality and consistency** for critical applications **Engineering Excellence Requirements:** - **Advanced ASME Section VIII Division 2** design methodology - **Sophisticated creep and rupture analysis** for extended service life - **Comprehensive fracture mechanics evaluation** using latest methodologies - **State-of-the-art fatigue analysis** for cyclic service conditions **Service Performance Guidelines:** - **Maximum design temperature**: 1150°F (621°C) for continuous service - **Minimum design temperature**: -50°F (-46°C) based on impact requirements - **Hydrogen service compliance**: Strict adherence to API 941 Nelson Curve criteria - **Oxidation performance**: Premium resistance in aggressive environments **Disclaimer:** This information represents the highest standard of technical reference for ASTM A542 Grade A Class 4. For ultra-critical pressure vessel applications, absolute adherence to the latest ASTM specifications and applicable ASME Code requirements is mandatory. All design, material selection, fabrication, and testing activities must be directed by exceptionally qualified engineers and subject to rigorous quality assurance protocols and regulatory oversight. -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel, Grade A, Class 4 Specification Dimensions Size： Diameter 20-1000 mm Length <4440 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ASTM A542 Low Alloy Steel, Grade A, Class 4 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A542 Low Alloy Steel Flange, Grade A, Class 4 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A542 Low Alloy Steel Flange, Grade A, Class 4 -:- For detailed product information, please contact sales. -:

Packing of ASTM A542 Low Alloy Steel Flange, Grade A, Class 4 -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 911 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition